Help Please: 2nd Row Dome Light ("Rear Room" Light) (1 Viewer)

[NicB]

Hi all,

I have a quirk with my '02 hundy that is driving me bonkers. When I bought the vehicle 5 years ago it had an aftermarket DVD player in the 2nd row roof. It was ugly and the drive was burnt out, so I pulled it and bought an OEM light to replace it (part #81260-60070). When I went to install it, the original wires coming out of the headliner had been clipped (no connector), so I cut the connector off the new part and crimped black to black, green to green, red to red (with a little extra wire spliced in for length). All good, right?

Problem is, when the switch is in the door position, the light does not come on when the door is opened. With the light in the on position, it lights up fine and the courtesy lights work individually. The off position turns the light off. Since it had power, I immediately ruled out the fuse (plus I checked it anyway and it was fine). My next thought was maybe it was a relay or something. However, the third row lamp comes on fine with either rear door open, as does the "door open" indicator in the instrument cluster. All I can think is that I wired it wrong and the colors on the incoming wires and the lamp itself do not match up like for like.

Last thing I would say is that the PO of this vehicle seemed to have a lot of accessories (remote start, DVD player, satellite radio, cell charger, etc.). The wiring under the kick panel has been modified and given how many wires are down there to begin with, I can't make heads or tails of it. While I have been able to remove all the non-working accessories at this point, I am hesitant to start un-taping wires and risk screwing something up that works today, especially when that wiring may be unrelated to my issue. I have looked at all the wiring diagrams and the TIS info on this topic, but none of it has helped.

Apart from this annoying me, my wife and I are expecting our first child and the extra light sure would help back there. Below is a picture of how I wired the light. Any help is appreciated, and if someone is willing to take a picture of how a stock light is wired I would be most grateful (it's easy to access...the plastic cover pops up and 4 phillips head screws hold the base in place).

Thanks all!
NicB

 

[Ayune]

@NicB You’ve wired it correctly according to the wiring diagram. The front & rear dome lights share power (red wires) and ground (white-with-black-stripe wires), but their door ‘enable’ wires are separate and controlled by the Instrument ECU located above your radio.

The center light’s door wire (green-with-white-stripe) is interrupted somewhere between the light and the ECU. Unfortunately, this signal passes through the nightmare of you driver’s kick panel junction box, but fret not, the diagram tells us it’s on pin 3 of connector 2A (see pics below). Find the upper-left connector on the junction box, that’s 2A. See if there’s a green-with-white-stripe wire at pin 3. If that’s ok, then you’ll have to check a couple other connectors... (see next post).

 

[NicB]

Solid feedback, thank you!!! I will investigate more tonight using your suggestions.

 

[Ayune]

This connector on the door side of the kick panel is likely unmolested since it’s pretty well buried, but pin 60 on this monster is how the door signal goes between the kick panel and the ECU. Should be a blue wire.

And finally, the blue wire ends up at the ECU above your radio via pin 2 of connector I19:

 

[NicB]

Ok, I'll look at this as well. Thanks!

 

[flintknapper]

Now that's providing help above and beyond. Good job @Ayune.

 

[NicB]

Ok, I finally had a chance to investigate today. The connectors were all untouched. No issues there. As I was sitting in the driver seat contemplating what to do next, I noticed a gap in the A-pillar molding. It reminded me that back when I first bought the car I had purchased a plastic screw cover because one was missing, which got me thinking maybe someone tampered with something in the A-pillar. Sure enough, once inside, I found the green and white wire had been cut!!! The side going to the dome light was connected to another brown wire which went down to the kick panel. This wire was loose and I pulled it out completely unconnected (had electrical tape on one end).

I thought, great, I just reconnect two green and white ends and I’m set! Wrong!!! After trying this, the light still won’t come on when the switch is at the door setting. Here is the really strange thing. When I put a multimeter on the gap in the wires and set the switch on the door setting, I get about 9.5v. When I move switch to off or on position, it reads 0v. This tells me power IS getting to the light through that green and white wire.

When I put the multi meter on the green/white to black terminals in the light itself, I get 12v.

Thoughts? Am I not getting enough voltage? Could there be a resistor somewhere else in the line? Here are a couple pics.

Any input to help me solve this is appreciated. I feel I am 95% there!

 

[Ayune]

The light bulb is the resistor, it will make your meter readings funny. Remove bulb to get a clear idea what the wires are doing. Ground one probe and touch the other to the wire you want to measure.

The green/white stripe wire is grounded by the ECU to turn the light on. It’s floating when the doors are closed so it may read a low, fluctuating voltage.

The red wire in the light housing is +12V.

 

[NicB]

The light bulb is the resistor, it will make your meter readings funny. Remove bulb to get a clear idea what the wires are doing. Ground one probe and touch the other to the wire you want to measure.

The green/white stripe wire is grounded by the ECU to turn the light on. It’s floating when the doors are closed so it may read a low, fluctuating voltage.

The red wire in the light housing is +12V.

I'll do that. The red wire is definitely 12v. Couple more thoughts/questions for you.

1. Right now, the light is dangling by the wires. Do you think I need to reinstall it / could there be a grounding element to the body frame?

2. After reading the owner's manual again, I noticed none of my interior lights come on when unlocking the door the way they should. That includes the ring around the ignition as well. This makes me think something else is messing with the lighting "signal" (for lack of a better term). The PO of my vehicle added various mods. Looking under the dash, I can tell there was a remote start at one point and I can see an inline fuse duct taped into something. I am hesitant to mess with that because I think it is unrelated and don't want something up and risk the car not starting. Could a remote start have hijacked the lighting functionality somehow?

3. Is any of the lighting functionality coded by the dealer (i.e., something I would need to get re-enabled)?

I appreciate your help. I am on a mission to figure this out!

Edit: post #28 of this thread gives me an idea of what likely happened with my ride. Ugh. Heads up on remote start from bestbuy

 

[Ayune]

3. Is any of the lighting functionality coded by the dealer (i.e., something I would need to get re-enabled)?

This could be the case, and probably the first thing I'd check. They added more Techstream functionality as the years went on so the only way to know what options you have is to plug in and see. Search the Techstream threads for info on that. I tried it once then quit since my '98 doesn't allow jack for customization.

1. Right now, the light is dangling by the wires. Do you think I need to reinstall it / could there be a grounding element to the body frame?

No, the center dome light does not need to mounted according to the wiring diagram. If you see a metal ring around one of the mounting screws then I could be wrong... The 3rd row light is like that.

2. After reading the owner's manual again, I noticed none of my interior lights come on when unlocking the door the way they should. That includes the ring around the ignition as well. This makes me think something else is messing with the lighting "signal" (for lack of a better term). The PO of my vehicle added various mods. Looking under the dash, I can tell there was a remote start at one point and I can see an inline fuse duct taped into something. I am hesitant to mess with that because I think it is unrelated and don't want something up and risk the car not starting. Could a remote start have hijacked the lighting functionality somehow?

The 'signal' that starts the process is any one of the doors being opened or the locks being unlocked. Next, the ECU selectively grounds the signals to the individual bulbs (and ignition cylinder ring) which are always powered by 12V and just waiting to be grounded. Given that you found a random cut wire behind the trim, anything is possible at this point, but it's unlikely that all of your door switch wires are cut. I'd start with Techstream and maybe looking under more trim.

 

[Ayune]

Just read this on another thread, it may help:
“My 1999 LC has maps up front, 2nd row and 3rd/cargo lights.
Opening driver door lights only the 2nd row light ie. above the center console/in front of the 2nd row.
Opening the 2nd row doors turns on the 3rd row/cargo light.”

 

[NicB]

Just read this on another thread, it may help:
“My 1999 LC has maps up front, 2nd row and 3rd/cargo lights.
Opening driver door lights only the 2nd row light ie. above the center console/in front of the 2nd row.
Opening the 2nd row doors turns on the 3rd row/cargo light.”

Yea, know this, just have to figure out how to make it work that way.

 

[NicB]

I have been watching a bunch of videos on removing car alarms and remote starters. I am 99% sure that I have either or both in my LC. Going to take a closer look tonight and see if I can figure out the brand and get the install manual (maybe I can reverse it to uninstall). Regardless, if I can get that crap out (including relays and inline fuses), then I have a hunch things will work as intended. I just have to be careful to make sure the car still starts!

 

[NicB]

Got the remote starter out. Installing one of these on any vehicle should be a crime. What a mess! I still have to finish cleaning up factory wiring and rejoin the ignition wire, but with any luck she’ll restart and lights will work too. There were multiple fuses and relays. Here are some pics of what I had under the dash!

 

[NicB]

Cleaned up the wiring from remote starter. Fortunately she restarted. Unfortunately, I am still getting low voltage on the green and white wire to the door. There is continuity from the A-pillar to the light. I’m not sure what else to try at this point. Any ideas appreciated. Very frustrating.

 

[LARRYG36]

Yeah we had one of those in ours that I just took out. I figured I’ll chase the wires when I take out the headliner because as you can see, whoever installed the DVD unit had to cut the headliner. Repairing a headliner is easy enough just a pain in the butt.

 

[NicB]

Still working this problem. I’ve determined I get 12v when shorting the green white wire in the A-pillar to ground and the light comes on! However, since this is upstream of all the “signal”, shutting or opening the door has no effect (light is always on). I’ve tested the dome relay, which is a bear to get to, and it is working. Wiring all seems good to the kick panel.

My hypothesis is there must be an open wire somewhere in the ground circuit between door switches and that A-pillar. Does this sound logical? Any additional ideas?

 

[Loves2na]

I'm actually having an issue with the third row dome light..when turned to on, works fine but on door the third row dome is dim as well as the second row door lights..also I was only reading about 8v when I checked it with my multimeter..can someone please assist. Thank you!

 

[mdcoa]

Resurrecting this one with a (somewhat) related question. I just installed an attic-rack net; when we fill it with coats it (surprise!) blocks the light from the 2nd row dome light . . .
Would like to mount some surface-mount LEDs, probably on the B-pillars, so I don't interfere with curtain airbags etc. . . . Could I run constant +12V to them and then run the grounds to the green/white wire (switched ground) from the dome light for them to work just like the (now-coat-covered) dome light?